Actively adjustable step-type ultrasonic horns in longitudinal vibration

2018 ◽  
Vol 419 ◽  
pp. 367-379 ◽  
Author(s):  
Shuyu Lin ◽  
Hao Guo ◽  
Jie Xu
Keyword(s):  
Longitudinal Vibration ◽  
Ultrasonic Horns ◽  
Step Type

scholarly journals Design and Analysis of a While-Drilling Energy-Harvesting Device Based on Piezoelectric Effect

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1266
Author(s):  
Jun Zheng ◽  
Bin Dou ◽  
Zilong Li ◽  
Tianyu Wu ◽  
Hong Tian ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Piezoelectric Material ◽  
Longitudinal Vibration ◽  
Coupling Model ◽  
Energy Harvest ◽  
Peak Voltage ◽  
Piezoelectric Patch ◽  
Theoretical Support ◽  
Piezoelectric Coupling ◽  
Continuous Power

A while-drilling energy harvesting device is designed in this paper to recovery energy along with the longitudinal vibration of the drill pipes, aiming to serve as a continuous power supply for downhole instruments during the drilling procedure. Radial size of the energy harvesting device is determined through the drilling engineering field experience and geological survey reports. A piezoelectric coupling model based on the selected piezoelectric material was established via COMSOL Multiphysics numerical simulation. The forced vibration was analyzed to determine the piezoelectric patch length range and their best installation positions. Modal analysis and frequency response research indicate that the natural frequency of the piezoelectric cantilever beam increased monotonously with the increase of the piezoelectric patch’ thickness before reaching an inflection point. Moreover, the simulation results imply that the peak voltage of the harvested energy varied in a regional manner with the increase of the piezoelectric patches. When the thickness of the piezoelectric patches was 1.2–1.4 mm, the designed device gained the best energy harvest performance with a peak voltage of 15–40 V. Works in this paper provide theoretical support and design reference for the application of the piezoelectric material in the drilling field.

A Flextensional Transducer Prototype with PVDF Piezoelectric Film

2014 ◽  
Vol 670-671 ◽  
pp. 1153-1158
Author(s):  
Jing Jing Liu ◽  
Lei Qin ◽  
Li Kun Wang ◽  
Chao Zhong ◽  
Bin Zhang ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Laser Scanning ◽  
Longitudinal Vibration ◽  
Voltage Response ◽  
Acoustic Measurement ◽  
Piezoelectric Film ◽  
Radial Vibration ◽  
Frequency Bandwidth ◽  
Metallic Shell ◽  
Flextensional Transducer

This paper presents a prototype of a new flextensional transducer with PVDF (Polyvinylidene Fluoride) piezoelectric film instead of metallic shell. Resonance frequency, bandwidth, transmitting voltage response, and horizontal directivity of the flextensional transducer with PVDF piezoelectric film were respectively measured by using laser-scanning vibrometer, and underwater acoustic measurement system. Experimental results showed that the new transducer features effectively conversion from longitudinal vibration of piezoelectric stack into radial vibration of PVDF piezoelectric film.

scholarly journals Semi-Analytical Solution for Free Vibration Differential Equations of Curved Girders

2017 ◽  
Vol 63 (1) ◽  
pp. 115-132
Author(s):  
Y. Song ◽  
X. Chai
Keyword(s):  
Analytical Solution ◽  
Differential Equations ◽  
Free Vibration ◽  
Coupling Effect ◽  
Longitudinal Vibration ◽  
Synthesis Method ◽  
Variable Separation ◽  
Element Analysis ◽  
Plane Vibration ◽  
Curved Girders

Abstract In this paper, a semi-analytical solution for free vibration differential equations of curved girders is proposed based on their mathematical properties and vibration characteristics. The solutions of in-plane vibration differential equations are classified into two cases: one only considers variable separation of non-longitudinal vibration, while the other is a synthesis method addressing both longitudinal and non-longitudinal vibration using Rayleigh’s modal assumption and variable separation method. A similar approach is employed for the out of- plane vibration, but further mathematical operations are conducted to incorporate the coupling effect of bending and twisting. In this case study, the natural frequencies of a curved girder under different boundary conditions are obtained using the two proposed methods, respectively. The results are compared with those from the finite element analysis (FEA) and results show good convergence.

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